The CU-210 controller is designed to control the water heater valve or electric heater and the fan speed depending on the temperature. The controller is operated from the keyboard on its housing and all parameters are presented on LED displays and LEDs. The controller has a MODBUS communication interface. Temperature can be measured using a built-in sensor or an external type PT 1000. The device has a voltage-free relay output and an analog output 0-10V.